Machine-to-machine (M2M) communication, also called Machine Type Communication (MTC), is the automatic exchange of information between end devices such as machines, vehicles or a control centre. Such communication does not necessarily need human intervention, and may not be resultant from initiation by a human user.
LTE (a standard technology developed by the 3rd Generation Partnership Project, 3GPP) cellular networks have been selected to support MTC applications since they offer a large coverage and they are all-IP networks. The benefits of such a deployment are complementary. For MTC applications, LTE offers good communications opportunities. For the providers of LTE networks, increased use of such networks enhances revenue. However, the deployment of MTC applications over LTE networks can imposes certain technical requirements.
It is envisaged that any deployment of MTC devices should expect a large number of such devices to be deployed in a specific area. In such a circumstance, the supporting communications network will experience increased average load, but may also encounter possible surges of MTC traffic.
As a result, network congestion may arise, such as in the form of Radio Network Congestion and/or Signalling Network Congestion. This could be the result of mass concurrent data and signalling transmission. This congestion may cause intolerable delays, packet loss or even service unavailability.
When the number of user equipment (UE) units deployed in a particular locality is within an acceptable range, it has been found that random access can provide efficient request delivery. However, the number of MTC devices could be far larger than the expected number of UE units. Investigations indicate that both MTC devices and UE may suffer continuous collisions at the random access channel (RACH) when a large number of MTC devices are involved.